# Demucs API

> Skiptir tónlistarlagi í aðskilda hljóðrása, svo sem söng, trommur, bassa, gítar og píanó, með vali á útfærslum

Aðskilur lag í einstakar hljóðfæraupptökur. Veldu Demucs-útfærslu með `model` (sjálfgefið htdemucs_6s, sem skilar einnig gítar og píanói), takmarkaðu úttakið með `stems` og stilltu gæði með `shifts` (1 til 10), `overlap` (0 til 1) og `segment_length`. Hljóðrásum er skilað sem mp3- eða wav-skrám, einni fyrir hverja upprunaskrá.

- Model id: `demucs`
- Made by: Meta
- Category: Audio
- Output: json
- Price per second of your input audio: $0.0007 / second of input audio (cheapest run $0.001 (1 API credit))
- Run: `POST https://api.doitong.com/v1/run/demucs`
- Quote: `POST https://api.doitong.com/v1/quote/demucs`
- Docs page: https://doitong.com/is/developers/models/demucs

## Pricing

Price: **$0.0007 / second of input audio**. Price per second of your input audio: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

The full example input below costs $0.007 = 7 API credits (10 s input audio × $0.0007).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.com/v1/quote/demucs` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `audio_url` | `audio` | string (audio URL) | yes |  |  | Vefslóð sem vísar á hljóðskrána fyrir aðgreiningu hljóðrása. |
| `model` |  | enum (string) | no | `htdemucs_6s` | `htdemucs`, `htdemucs_ft`, `htdemucs_6s`, `hdemucs_mmi`, `mdx`, `mdx_extra`, `mdx_q`, `mdx_extra_q` | Demucs-líkan valið fyrir aðgreiningu hljóðrása. |
| `stems` |  | array of enum (string) \| null | no | `["vocals","drums","bass","other","guitar","piano"]` |  | Val á hljóðrás úr tiltækum valkostum líkansins: vocals, drums, bass, other, guitar, piano (fyrir 6s-líkanið). Stilltu á None til að draga út allar hljóðrásir sem líkanið býður upp á í stað tiltekins vals. |
| `segment_length` |  | integer \| null | no |  | ≥ 1 | Lengd vinnsluhluta í sekúndum, með sjálfgefnu gildi sem er háð líkaninu. Minni lengd dregur úr minnisnotkun en getur skert gæði; lágmarkið er 1. |
| `shifts` |  | integer | no | `1` | 1 – 10 | Fjöldi slembihliðrana í jafngildisstöðgun; fleiri hliðranir auka vinnslutíma en bæta gæði. |
| `overlap` |  | number | no | `0.25` | 0 – 1 | Skörun hluta eykur vinnslutíma en getur bætt gæði; leyfilegt bil er 0.0–1.0. |
| `output_format` |  | enum (string) | no | `mp3` | `wav`, `mp3` | Hljóðsnið sem notað er til að vista aðgreindu hljóðrásirnar. |

File parameters (`audio`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{
  "audio": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

A fuller example:

```json
{
  "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/demucs?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.com/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/demucs?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.com/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/demucs", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.com/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "demucs",
      "input": {
        "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "demucs",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 7,
    "usd": "0.007",
    "charged": 7,
    "refunded": 0
  },
  "input": {
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  },
  "output": {
    "vocals": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_name": "0-output.jpeg",
      "file_size": 1843200
    },
    "drums": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_name": "0-output.jpeg",
      "file_size": 1843200
    },
    "bass": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_name": "0-output.jpeg",
      "file_size": 1843200
    },
    "other": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_name": "0-output.jpeg",
      "file_size": 1843200
    },
    "guitar": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_name": "0-output.jpeg",
      "file_size": 1843200
    },
    "piano": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_name": "0-output.jpeg",
      "file_size": 1843200
    }
  },
  "outputs": [
    {
      "type": "file",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_size": 1843200,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `vocals` | object {url, content_type, file_name, file_size} \| null | Hljóðskrá sem inniheldur einangraðan söng. |
| `drums` | object {url, content_type, file_name, file_size} \| null | Hljóðskrá sem inniheldur einangraða trommur. |
| `bass` | object {url, content_type, file_name, file_size} \| null | Hljóðskrá sem inniheldur einangraðan bassa. |
| `other` | object {url, content_type, file_name, file_size} \| null | Hljóðskrá sem inniheldur önnur einangruð hljóðfæri. |
| `guitar` | object {url, content_type, file_name, file_size} \| null | Hljóðskrá sem inniheldur einangraðan gítar, aðeins tiltæk með 6s-líkönum. |
| `piano` | object {url, content_type, file_name, file_size} \| null | Hljóðskrá sem inniheldur einangrað píanó, aðeins tiltæk með 6s-líkönum. |

## Related models

- [MMAudio V2](https://doitong.com/developers/models/mmaudio-v2.md) (`mmaudio-v2`): $0.001 / second
- [Sam Audio · Separate](https://doitong.com/developers/models/sam-audio/separate.md) (`sam-audio/separate`): from $0.05 / 30 seconds of input audio
- [Sam Audio · Span Separate](https://doitong.com/developers/models/sam-audio/span-separate.md) (`sam-audio/span-separate`): from $0.05 / 30 seconds of input audio
- [DeepFilterNet 3](https://doitong.com/developers/models/deepfilternet3.md) (`deepfilternet3`): $0.001 / second of input audio
- [ElevenLabs Audio Isolation](https://doitong.com/developers/models/elevenlabs/audio-isolation.md) (`elevenlabs/audio-isolation`): $0.10 / minute of input file
- [Elevenlabs Sound Effects V2](https://doitong.com/developers/models/elevenlabs/sound-effects/v2.md) (`elevenlabs/sound-effects/v2`): $0.002 / second
- [ElevenLabs Voice Changer](https://doitong.com/developers/models/elevenlabs/voice-changer.md) (`elevenlabs/voice-changer`): $0.30 / minute of input audio
- [FFmpeg API \[Merge Audios\]](https://doitong.com/developers/models/ffmpeg-api/merge-audios.md) (`ffmpeg-api/merge-audios`): $0.00017 / second of processing time

## Links

- HTML page: https://doitong.com/developers/models/demucs
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=demucs
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/demucs